(a) Field of the Invention
The present invention relates to a driving apparatus and a driving method of a light emitting diode (LED) device.
(b) Description of the Related Art
An LED device supplies a current to LEDs to drive them, and the LEDs emit light having brightness corresponding to the current. The LED device may be used as a light source of a non-emissive type of display device such as a liquid crystal display (LCD) or for lighting. The LED device includes a plurality of LED channels that are connected in parallel to emit light having predetermined brightness. Each LED channel includes a plurality of LEDs connected in series. Further, the LED device includes a power converter for supplying the currents to the plurality of LED channels.
In a case that a plurality of LED channels are used, a connection between two LEDs of a certain LED channel can become open-circuited. If the open-circuited LED channel is not detected, the power converter provides the maximum voltage to a plurality of LED channels, which can increase power consumption and cause a heating problem.
One example of detecting the open-circuited LED channel is a circuit for providing the maximum voltage to a plurality of LED channels and measuring a voltage of a terminal of each LED channel to regard an LED channel with a terminal voltage of 0V as the open-circuited LED channel. However, the maximum voltage is provided for finding the open-circuited LED channel, so it can increase power consumption and cause a heating problem.